VOR Check question

"Mike Rapoport" wrote in news:HZrFe.8543$dU3.6278
@newsread2.news.pas.earthlink.net:

My understanding is that WAAS has an integrety function and is able to
detect an inaccurate signal.

RAIM (Receiver Autonomous Integrity Monitoring) is available without WAAS,
and was available before WAAS was implemented.

--
Regards,

Stan

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." B. Franklin

"Jose" wrote in message
. ..

I would assume (and I know the etymology) that VORs fail 1000 square miles
at a time, and GPS fails 3,000,000 square miles at a time. Or, more to
the point, there is more systemic redundancy in the VOR system.


The question was, "So why is it presumed that the VOR system cannot fail?",
not, "So why is it presumed that a VOR cannot fail?" The loss of a GPS
satellite would not render the GPS system unusable.

"Stan Gosnell" wrote in message
...
"Mike Rapoport" wrote in news:HZrFe.8543$dU3.6278
@newsread2.news.pas.earthlink.net:

My understanding is that WAAS has an integrety function and is able to
detect an inaccurate signal.

RAIM (Receiver Autonomous Integrity Monitoring) is available without WAAS,
and was available before WAAS was implemented.

--
Regards,

Stan


I'm aware of that. The WAAS signal was to contain another
intergrety/availiblity function.

Mike
MU-2

The question was, "So why is it presumed that the VOR system cannot fail?",
not, "So why is it presumed that a VOR cannot fail?" The loss of a GPS
satellite would not render the GPS system unusable.

.... and my response addresses exactly that. The failure of a single VOR
(or even twenty) won't cripple the VOR system. But the (albeit
unlikely) failure of twenty satellites will cripple the GPS system.
There is more systemic redundancy in the VOR system, just by virtue of
there being more VORs, and by virtue of the fact that a single VOR
affects a relatively small area.

Jose
--
Nothing takes longer than a shortcut.
for Email, make the obvious change in the address.

Remember.
ALL FAR's are written to violate the pilot.

Stan Gosnell writes:

My understanding is that WAAS has an integrety function and is able to
detect an inaccurate signal.

RAIM (Receiver Autonomous Integrity Monitoring) is available without WAAS,
and was available before WAAS was implemented.

Look up FDE "fault detection / exclusion" instead. This computation
is possible to perform without WAAS (the GNS430 does some now), but
WAAS carries satellite health flags that simplify it.


- FChE

91.205(d)(2) is exactly the point. If a pilot is using VOR ground
facilities, a VOR receiver would be appropriate. If he's not (e.g.
using TACAN or GPS), a VOR receiver would not be appropriate and
therefore not required.

Support for the anti-requirement is in 91.205(e), which specifically
accounts for flying IFR without a VOR.

"Steven P. McNicoll" wrote:

wrote in message ...

Well, okay, but I work with this stuff all the time.


That doesn't mean you understand it.


Here is from the current FAA Order 8260.19C:

l. Dual Minimums. Enter dual minimums, when authorized. Do not publish
dual minimums unless a 60-foot operational advantage is obtained or a
reduction in visibility can be achieved. To avoid proliferation of dual
minimums, *all IFR aircraft are assumed to have at least one VOR
receiver*. Dual minimums based on a stepdown fix combined with local and
remote altimeter settings could result in four sets of minimums. When two
remote sources are used, treat the source resulting in lower minimums as
the "LOCAL" altimeter setting source in the following paragraphs.
Document only two sets of minimums. The combinations authorized are
minimums with and without a stepdown fix; or minimums with local and
remote altimeter settings.

The words between the asteriks are reflective of FAA Class I navigation
policy, which is a requirement to be a part of ICAO.


FAA Order 8260.19C places no regulatory requirements upon pilots or the
operation of aircraft.

Sure it does. It provides guidance for minimums, procedural data notes, etc,
which
are Part 97 imperatives when transmitted through the rule-making process onto
the
approach chart. Obviously, you don't know what you're talking about.



How are you doing with that reference for the timing tables on NACO charts
being IAS?

Those are "speeds." How you choose to use them is up to you. The regulatory
basis is the
distance from the FAF to the MAP. Nothing more, nothing less. Obviously, with
today's
equipment navigating to the MAP via RNAV is more accurate than a pilot attempt
to
convert IAS to TAS, then to G/S.

On Sat, 23 Jul 2005 04:41:18 -0700, wrote:

Not so. VOR is still the primary means of navigation in the NAS. Even the
latest and greatest airline aircraft with dual GPS sensors, dual FMSes, triple
IRUs, etc, cannot be dispatched without operate VOR receivers (in their case
two).

The presumption is that the GPS system can fail at any time; at least in a given
area. WAAS doesn't mitigate that whatsoever.

Could you reconcile your statement with AIM 1-1-20 c.

"7. Unlike TSO-C129 avionics, which were certified as a supplement to other
means of navigation, WAAS avionics are evaluated without reliance on other
navigation systems. As such, installation of WAAS avionics does not require
the aircraft to have other equipment appropriate to the route to be flown."


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Brien K. Meehan" wrote:

91.205(d)(2) is exactly the point. If a pilot is using VOR ground
facilities, a VOR receiver would be appropriate. If he's not (e.g.
using TACAN or GPS), a VOR receiver would not be appropriate and
therefore not required.

Support for the anti-requirement is in 91.205(e), which specifically
accounts for flying IFR without a VOR.

You're reading the regulation without the context of FAA policy. VOR is
still the primary en route nav aid. Write FAA Flight Standards in DC
and ask them if the regulation means what you think it means.